Bridge



(No Model.) 2 Sheets-She t 2.

W. HARMAN.

BRIDGE.

No. 383,880 Patented June 5, 1888.

WILLIAM HARMAN, OF OAK PARK, ILLINOIS.

BRIDGE.

SPECIFICATION forming part of Letters Patent No. 383,880, dated June 5,1888.

Application filed March 10, 1888. Serial No. 267.771. (No model.)

To aZZ whom it may concern:

Be it known that I, WILLIAM HARMAN, residing at Oak Park, in the countyofOook and State of Illinois, and a citizen of the United States, haveinvented a new and useful Improvement in Bridges, of which the followingis aspccification, reference being had to the accompanying drawings, inwhich- Figure 1 is a longitudinal vertical section showing one half ofthe bridge lowered in posit-ion for crossing and the other half raised;and Fig. 2 is a view in elevation of the half shown at the left-handside of Fig. 1, the water-way with the under passages being in section.

In cities where bridges are used forcrossing navigable waterways it isvery desirable that the construction of the bridges be such as to enablethem to be operated rapidly in opening and closing, and thus delaytravel across the bridge for as short a time as possible, and at thesame time allow a rapid movement of the vessels passing through. Thebridges in general use in such places are pivot or swing bridges, orthose supported by a central pier,

, which are objectionable on account of the time consumed in opening andclosing them, it being necessary to commence to swing the bridge sometime before the near approach of a vesso], and are objectionable tothose navigating the water-way on account of the central pier or supporton which the bridge rests occupying the center of the water-way, so thatin many cases it is difficult to properly steer the boat so as not tocollide with the bridge or its approaches, and many accidents occurwhich would otherwise not happen were the center supportingpier notused, and there is less liability to ground, as the channel is usuallydeeper in the middle.

Draw-bridges are not open to the objection of obstructing the channel bytheir supports; but as heretofore made they have not been practical foruse over any but narrow channels, as when made in either one or twosections they are too heavy,ifproperly constructed for city traffic, tobe quickly and easily raised and lowered.

My improvements overcome these obj ections and produce a bridge which isstrong and durable,- and its nature consists in making the bridge inhalves and each half in sections hinged together; in attaching thelifting-cables at or near the section-hinges, so that when the bridge isopened the inner section of each half will be raised and the othersection will fold in against the under side of the inner section, and inthe several parts and combinations of parts, hereinafter morespecifically described, and pointed out in the claims as new. a

In the drawings, A represents the outer floorsection of each half of thebridge, and B are the inner floor-sections.

G are standards.

D are brace-bars for the standards 0.

E are rods extending from each section A to the standards 0, or to across-girder, g, extending from standard to standard.

F and G are operating ropes or chains.

H is a winding-drum.

I is a weight.

J are the abutment-s.

a is a rod or shaft on which the sections A B are hinged together.

b is a rod or shaft similar to a, on which the inner end of each sectionB is hinged.

c are brackets on the standards 0.

d are turn-buckles.

c e are pulleys or rollers.

f are guard-railings on the sides of the bridge.

g is a girder or crossbar.

h are braced standards or looks to prevent sagging at the joints a andto relieve strain.

The bridge shown is designed for the full width of a sixtysix or eightyfoot street, and fora bridge of this size the framework of the sectionsA B is made of suitable wrought-iron, and the floor-planks are attachedthereto by bolts and spikes. The standards 0 may be made of cast'iron,or of suitable wrought-iron frame or truss work, and the cross-girders,when used, may be made of cast-iron sections, or in a continuouswrought-iron truss. The height of the standards will depend somewhatupon the length of the bridgespan; but they should be of a sufficientheight to give the floor-sections an easy movement. The hinges betweenthe floor-sections of each half are best made by providing each sectionwith any desired number of suitable eyes located at or below the lowerline of the frames and connecting them together by a continuous strongrod,

or a shaft, to which the lifting-chains are attached. For the purpose ofholding the adjoining edges or ends of the halves in line when they arelowered or swing into position, the edge of one may be grooved, as at z,and the edge of the other provided with acorresponding bevel. If astronger connection for this i point is desired, locking-bloclgs orremovable bolts may be added.-

The rods E are adjusted by means of the turn-buckles (I, so as to berigid and hold the bridge firmly to prevent sagging at the middle, andwhen the sections A are being moved into or out of position the endsthereof will be given a firm support during such operation. The freeends of the sections A will move in the arc of a circle,which allows ofthe adjoining edges being made one concave and the other convex.

The ropes or chains F, which are on the same side as the drum H, passfrom such drum up to and over pulleys secured on the bracket c, down tothe point of attachment to the section B. The corresponding cables orchains F that raise the opposite section B pass from the drum H down andunder the bed of the waterway through one or more suitable shafts ortunnels, up to and over pulleys secured to the brackets 0, down to thepoint of attachment to the other section B.

The ropes or chains G, which are on the same side as the drum H, areconnected at one end to such drum, and from thence pass over pulleys orrollers to the point of attachment to the section B. The correspondingcables or chains G, used for lowering the opposite section B, pass fromthe drum H, to which they are connected, to the opposite side of thewaterway, passing through the same shafts or tunnels as the ropes orchains F, thence over pulleys or rollers to the point of attachment tothe section B. As shown, the points of attachment of the cables orchains G to the sections B are opposite the points of attachment of thecables or chains F to the same sections.

When the shaft H is rotated in the direction of the arrow, Fig. 1, thecables or chains F will be wound thereon and draw the section in toallow vessels to pass, as will be hereinafter more fully described.WVhen the rotation of the shaft is reversed, the cables F will beunwound and the cables G wound thereon, the effect of the winding of thecables G being to cause them to pull downward on the section B, whichdownward pull is continued until the sections are horizontal or inposition. The sections B, when being lowered, will force the sections Ainto a horizontal position also, the rods E serving to support and guidethem while moving into place, and when in place holding them firmly.

In closing the bridge the drum H will be rotated only sufficient tounwind enough of the ropes or chainsF topermit such ropes or chains toextend, in a taut condition, from the drum to and over the pulleys inthe brackets c to the points of attachment to the sections B. The

rotation of the drum to unwind the cables or chains F will not usuallybe sufficient to take up all of the slack of the cables or chains G. Totake up such slack,l have provided weights I, which are attached to thecables or chains G between two pulleys, e e, each weight being raisedand lowered in suitable wells or chambers formed in the abutments J.

As shown, guard-railings f are secured to the'sides of the bridge, whichrailings are of the same length as the sections to which they aresecured. On the left-hand side of Fig. 1 these railings are shown indotted lines to indicate their position when the bridge is open. It isdesirable that when closed the adjoining ends of the guard-rails comeclosely together, and by beingfornied of stronger timbers or framing han extra bracing or support is atforded, which prevents vibration andstrengthens the bridge. 1

If it is not desirable or convenient to operate both sides of the bridgeby means of cables passing underneath the bed of the river or otherwater-way, each half may be operated separately, and in such case itwill not be necessary to operate the halves simultaneously, and in somecases it will not be necessary to operate more than one half to permitthe passage of a vessel, or tomove both entirely back when both areoperated.

When the bridge is open, the sections B form effectual guards forpreventing accidents by absence of mind or by runaway teams, &c.

The bridge is intended to be of the same width as the street leading toit, and is to be provided with as many rods E as desired or arenecessary. As shown in Fig. 2, five are provided, which serve to dividethe bridge into different divisions for foot-passengers and vehicles.The girder or cross-bar 9, connecting the tops of the standards 0,furnishes the means of attaching the upper ends of the intermediaterods, E.

It will be seen that by dividing each half of the bridge into sectionsand raising from the joints a or sections B, instead of from the outersections, A, a much less expenditure of power is required to operate thebridge in opening or closing, and that either movement can beaccomplished in much less time than is required to move undividedhalves, as the are described by the end of B will be much smaller thanwould be the case if the sections A were swung up in the same planes asthe sections B.

The operation is as follows: Suppose the bridge to be down or inposition for use and it is desired to open it. Power is applied to thedrum H, which winds thereon the chains or cables F,which are eachsecured at one end tothe drum and at the other end to the rods or shaftsa of the section-hinges or to eyes at the forward edges of the sectionsB, thus raising the sections B, and as these sections are raised thesections A,which are supported by the rods E, fold down sufficiently topass the outer edges of the abutments J the upper portion of whichabutments may be recessed or cutaway to receive and protect the sectionsA. The position of the sections will then be as represented by theleft-hand side of Fig. 1,

from which it will be seen that the bridge is entirely withdrawn fromover the water-Way, leaving the entire channel free for the passage ofvessels. In lowering, a reverse movement is given to the drum or shaftH,and the halves are drawn back by the cables or chains G, thus givingthe halves a positive movement, and preventing any sudden movements andthe dropping of the floor-sections into position, which is liable totakeplace when partly down, owing to their being supported on the rods Eand the hinges or pivots b. By this construction of a draw-bridge Iadapt it to much wider channels than draw-bridges have heretofore beencapable of spanning, and I bring the floors to a level or horizontalposition, whereby the necessity of forming abntments capable ofresisting pressure is avoided and the necessity of lowering the halvessimultaneously overcome, as the halves may be separately lowered. I alsoavoid raising the outer portions of the draw-halves to a away with thenecessity for high standards, the sections so nearly counterbalancingeach other, and I carry so large a proportion of the weight upon thepermanent structure that comparatively little power is required to movethe bridge. By shortening the sections B within proper limits lessmoving power will be required and a more rapid movement of the partscovering the passage will take place.

Steam-power will be required to operate a bridge of the described size;but smaller wooden bridges may be operated by manpower, and for canalsor other narrow channels the folding sections of one half may be used asa complete bridge.

The outside tunnels or under passages may great height, do

be made large enough for foot-passengers, and in that event all of thecross operating cables or chains will be taken through such passage orpassages, and when such under passages are omitted each half willrequire separate applications of power.

By properly adjusting the weight of the sections A B, the cables orchains F may be used for both raising and lowering, for the weight ofthe sections will carry them into position for use, and a brake may beapplied to the shaft or drum H to prevent rapid descent; but for heavybridges the cables or chains G are essential. v

\Vhat I claim as new, and desire to secure by Letters Patent, is

l. A draw-bridge composed of halves or two parts, each part consistingof sections, as A B, hinged together, substantially as and for thepurpose specified.

2. The combination of the sections A B, hinged together, standards 0,rods E, and ropes F, for raising the sections B to open the bridge,substantially as specified.

3. The combination of the sections A B, hinged together, standards 0,rods E, and ropes G, for lowering the sections B to close the bridge,substantially as specified.

4. The combination of the sections A B, hinged together, standards 0,rods E, ropes F G, and winding shaft or drum H, for raising and loweringthe sections B to open and close the bridge, substantially as specified.

5. In a draw-bridge, the hinged floor-sections A B, supported andarranged to fold to gether when lifting-power is applied to theabutmentsection, substantially as described.

\VILLIAM I-IARMAN.

Witnesses:

ALBERT H. ADAMS, HARRY T. J ONES.

